/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
class Solution {
public:
    bool hasPathSum(TreeNode* root, int targetSum) {
        if(root == nullptr) return false;
        if(root->left == nullptr && root->right == nullptr) return targetSum == root->val;
        return hasPathSum(root->left, targetSum - root->val) || hasPathSum(root->right, targetSum - root->val);
    }
};


class Solution {
public:
    bool dfs(TreeNode* root, int target, int sum)
    {
        if(root == nullptr) return false;
        sum += root->val;
        if(root->left == nullptr && root->right == nullptr) 
        {
            if(sum != target) return false;
            else return true;
        }
        return dfs(root->left, target, sum) || dfs(root->right, target, sum);
    }   
    bool hasPathSum(TreeNode* root, int targetSum) {
        return dfs(root, targetSum, 0);
    }
};
